Volume Analysis of Arthroscopic Capsular Shift

Purpose: To determine how much volume reduction can be obtained with varying amounts of arthroscopic capsular plication. Methods: Six fresh-frozen, cadaveric specimens were used. Specimens were rejected if a rotator cuff tear was present. The volume of each shoulder joint was measured under 3 conditions: no capsular shift, 5-mm capsular shift, and 10-mm capsular shift. For each shift, 4 sutures were placed arthroscopically, 2 anteriorly and 2 posteriorly. Repeated measures were used to confirm the validity of the measurements. Data were analyzed with parametric and nonparametric tests. Results: The average percentage of volume reduction at 5 mm of capsular plication from control was 16.2% (range, 9.7% to 21.5%). The percentage of volume reduction from control to 10 mm of capsular plication averaged 33.7% (range, 25.3% to 44.6%). Statistical significance was found with both parametric ( P < .0001) and nonparametric tests ( P < .0313). Conclusions: The current study found that capsular volume reduction was related to the amount of capsular plication with reproducible results. Capsular plication can produce volume reduction comparable to other techniques. Clinical Relevance: The data could be used to determine the potential number of sutures and amount of tissue plication needed for the amount of laxity found at surgery.